Detection and Determination of α(2)-MacroglobulinTrypsin Activity in Pleural Fluids and Ascites

Abstract

Pancreatic effusions are able to hydro- lyze BAPNA, a specific substrate of trypsin. Gel filtration on Sephadex G-200 indicates that this activity is due to α(2)-macroglobulin-bound trypsin. The presence of α(2)M-trypsin complexes is further substantiated by the behaviour of the tryptic activity toward inhibitors of increasing molecular weights. Tryptic activity was found not only in pancreatic effusions but also in a small number of non pancreatic ascitic fluids. No correlation exists between this activity and the α(2)M or amylase content. These results, as well as the absence of chymotryptic activity are discussed in view of the known binding properties of α(2)-macroglobulin.